1. Field of the Invention
The present invention relates to a buckle and, more specifically, to a buckle which can be moved in the longitudinal direction of a web-like material (e.g. a tape, a belt or a flat strap) and also can be fixed in an optional position.
2. Description of Related Art
As a buckle capable of being moved in the longitudinal direction of a web-like material and being fixed in an optional position, which comprises a first member and a second member displaceably provided in the first member, for example, a buckle disclosed in Japanese Utility Model Application Laid-open H5-31926 (Conventional Example 1) or Japanese Utility Model Application Laid-open H4-9841 (Conventional Example 2) is well-known.
The buckle of the Conventional Example 1 comprises a buckle main body and a stopper piece. The buckle main body comprises a pair of side frames, an attachment shaft provided over one edge between a pair of the side frames, a winding shaft provided over the other end between the pair of side frames and a guide shaft. One end of the stopper piece is rotatably supported in between the side frames on the attachment shaft side. Further, the stopper comprises an engagement protrusion on the other end for fastening a belt between with the winding shaft.
In this structure, one of the belts is attached to the attachment shaft. After winding the other belt around the winding shaft and reversing it, the engagement protrusion of the stopper piece is pushed into the reversed face of the belt. Thereby, the reversed face of the belt is engaged with the winding shaft by pressure in the side face of the engagement protrusion. That is, the belt is engaged with the buckle in an optional position in the longitudinal direction.
The buckle of the Conventional Example 2 comprises a buckle main body and a stopper. The buckle main body comprises a pair of side frames, a pair of bearing grooves formed on one end of the pair of side frames, a winding shaft and a guide shaft provided over the other end between the pair of side frames. The stopper piece comprises a protrusion shaft which is engaged with the winding shaft provided on one end and the bearing grooves, and an engagement protrusion provided in the other end for fastening the belt between with the winding shaft.
In this structure, one of the belts is attached to the attachment shaft. After winding the other belt around the winding shaft and reversing it, the engagement protrusion of the stopper piece is pushed into the reversed face of the belt. Thereby, the reversed face of the belt is engaged with the winding shaft by pressure in the side face of the engagement protrusion. That is, the belt is engaged with the buckle in an optional position in the longitudinal direction.
However, both buckles described above have the structure which prevents shift of the belt by pinching the belt between the engagement protrusion of the stopper piece and the winding shaft. Thus, it is necessary to precisely fabricate the buckles so that, when the stopper is rotated, the space between the engagement protrusion of the stopper piece and the winding shaft becomes smaller than the thickness of the belt by appropriate amount. Therefore, it becomes necessary to fabricate each part with high precision thereby increasing the cost. If the space between the engagement protrusion of the stopper piece and the winding shaft is not smaller than the thickness of the belt by appropriate amount, there may face following problems.
For example, if the space between the engagement protrusion of the stopper piece and the winding shaft is extremely smaller than the thickness of the belt, it requires a force to rotate the stopper piece. Thus, the force is applied to the stopper piece and the buckle main body which rotatably supports the stopper. Therefore, these parts are likely to be damaged.
Inversely, if the space between the engagement protrusion of the stopper piece and the winding shaft is extremely larger than the thickness of the belt, the force for pinching the belt becomes insufficient so that the shift of the belt cannot be surely prevented.
Further, when being repeatedly used for a long period of time, it is possible that the engagement protrusion of the stopper becomes slippery due to wear. Therefore, the shift of the belt cannot be surely prevented. In other words, it is likely to cause deterioration in the fixing function due to wear.
The present invention has been designed to overcome the foregoing problems. An object of the present invention is to provide a buckle in which each part is not required to be fabricated with high precision, which is capable of moving and fixing by simple operation, suffers less damage for a long period of time and, at the same time, is capable of preventing the deterioration in the fixing function.
A buckle of the present invention comprises a first member and a second member which is provided displaceable in the first member. The first member comprises a base part, at least two insertion parts provided in the base part with a space in between to which the web-like material is inserted, and a bending part provided in between the two insertion parts for bending the web-like material in a direction away from the base part. The second member is displaceable to a first position where the buckle can be moved against the web-like material and to a second position where the buckle can be fixed to the web-like material, and comprises a pressurizing part for pressurizing one side of the web-like material in a bent state towards the other side so as to obtain a further bent state in the second position.
When pressurizing one side of the bent web-like material towards the other side thereby to further bend it, the web-like material may come to be in contact with the bent part and the pressurizing part. However, it is not necessary that the web-like material be fastened by a strong force being pinched between the bent part and the pressurized part as long as the bent state of the web-like material serves as resistance to the shift of the buckle thereby to restrict the shift of the buckle.
In this structure, the web-like material, for example, is pulled out from one of the insertion part via the bending part, after being inserted to the other insertion part. When the second member is placed in the first position, the buckle is in a movable state against the web-like material so that the buckle can be moved to an optional position of the web-like material in the longitudinal direction. In the case of moving the web-like material against the buckle, the web-like material can be moved against the buckle in the longitudinal direction.
When moving the second member to the second position, the pressurizing part of the second member pressurizes the one side of the bent web-like material towards the other side thereby to further bend it. Thus, the shift of the buckle against the web-like material is restricted so that the buckle can be fixed in an optional position of the web-like material in the longitudinal direction.
As described, it is a structure that the buckle is fixed by the pressurizing part of the second member, which pressurizes one side of the bent web-like material towards the other side so as to further bent the web-like material. In other words, it is not a structure in which the buckle is fixed through fastening the web-like material by a strong force being pinched between the bent part and the pressurizing part. Therefore, unlike the related art, it is not necessary to fabricate each part with high precision. Further, because of the same reason, that is, it is not the structure in which the buckle is fixed through fastening the web-like material by a strong force being pinched between the bent part and the pressurizing part, moving and fixing operations of the buckle can be easily performed. Also, it suffers less damage for a long period of time and, at the same time, prevents the deterioration in the fixing function.
In the buckle of the present invention, the bending part is composed of an upstanding piece which stands sloping up towards a direction away from the base part as it reaches the other insertion part from the base part in the vicinity of one of the insertion parts. The pressurizing part, in the second position, is to be substantially in the same position as a perpendicular line drawn from the tip of the upstanding piece to the base part or to be protruded to inner side of the upstanding piece than the perpendicular line.
In this structure, when the second member is in the second position, the pressurizing part is in substantially the same position as the perpendicular line drawn from the upstanding piece or protruded inner side of the upstanding piece than the perpendicular line. Therefore, the web-like material is to be bent in Z-shape or reversed S-shape so that the shift of the buckle can be more surely restricted.
Further, it is preferable that the upstanding piece stand up sloping against the base part at an angle of 35xc2x0 to 55xc2x0.
In this structure, the upstanding piece stands up sloping against the base part at an angle of 35xc2x0 to 55xc2x0 so that the thickness of the buckle can be suppressed while maintaining the function of restricting the shift of the buckle. In other words, if the angle of the upstanding piece is increased, bending height of the web-like material from the base part (that is, rising height) is also increased, thereby increasing the resistance at the time of moving the buckle. Therefore, the function of restricting the shift of the buckle is improved while the thickness of the buckle is increased. Inversely, if the angle of the upstanding piece is reduced, the thickness of the buckle can be decreased while the function of restricting the shift of the buckle is deteriorated. On the contrary, by providing the upstanding piece at an angle within the above-described range against the base part, both functions described above can be sufficiently achieved.
Further, it is preferable that the tips of the upstanding piece and the pressurizing part be formed at an angle of 90xc2x0 or less.
In this structure, both tips of the upstanding piece and the pressurizing part with which the bent web-like material is to be in contact are formed at an angle of 90xc2x0 or less. Therefore, the corners of the tips are to be engaged with the web-like material so that the function of restricting the shift of the buckle can be further improved.
Also, it is preferable that the second member be rotatably supported by the base part in between the two insertion parts of the first member.
With this structure, the second member can be easily moved between the first position and the second position by simply rotating it. Thus, the operation can be easily and smoothly performed.
Further, it is preferable that the second member comprise a pinching part for pinching the web-like material between with the base part of the first member when the second member comes to be in the second position.
With this structure, when the second member is in the second position, the web-like material is further bent by the pressurizing part of the second member and, at the same time, it is pinched between the pinching part of the second member and the base part of the first member. In other words, the resistance between the web-like material and the buckle is further increased. As a result, the function of restricting the shift of the buckle can be further improved.
Furthermore, it is preferable that the second member comprises a length adjustor capable of restricting shift of the inserted other web-like material in an optional position in a length direction, to which other web-like material than the web-like material is inserted.
With this structure, moving and fixing operation of the buckle in an optional position of the web-like material in the longitudinal direction and adjusting the length of the other web-like material can be achieved by one buckle. Therefore, when it is applied to the conventional rucksack structure, the number of parts can be reduced, thereby reducing the cost while improving the operability.
FIG. 8 and FIG. 9 show the conventional rucksack structure. The rucksack comprises a rucksack main body 1, a pair of carrying belts 2 provided on both sides of shoulder part of the rucksack main body 1, and a support belt 3 for connecting the upper part of the carrying belts 2 and the upper part of the rucksack main body 1. The carrying belts 2 comprises two belts 2A and 2B whose one ends are fixed to the rucksack main body 1, and a connector 2C for connecting the ends of the two belts 2A and 2B while enabling to adjust the length of the belt 2B. The support belt 3 comprises two belts 3A and 3B, a connector 3C for connecting the ends of the two belts 3A and 3B while enabling to adjust the length of the belt 3A, and a connector 3D which is provided movable in the longitudinal direction of the belt 2A and connects to the other end of the belt 3A.
With this structure, it requires three connectors such as the connector 2C, the connector 3C and the connector 3D. That is, a large number of parts are required thereby increasing the cost. Also, the adjusting operation needs to be performed in each position of the connectors 2C, 3C, and 3D. In other words, operation needs to be performed in three different positions resulting in lack of operability.
The structure of the present invention is designed to overcome such a problem. In other words, when the buckle according to the present invention, which comprises, in the second member, a length adjustor capable of restricting shift of other inserted web-like material in an optional position in a length direction, to which other web-like material different form the web-like material is inserted, is employed, for example, in the position of the connector 3D in FIG. 8 and FIG. 9, reduction in the number of the parts and cost, and improvement in the operability can be expected. In other words, by employing the structure of the present invention to the rucksack structure shown in FIG. 8 and FIG. 9, the connector 3C can be omitted and, at the same time, operation is required only in two positions such as in the connector 2C and the buckle of the present invention. Thus, the operability can be more improved compared to the related art.
Further, it is preferable that the length adjustor be composed of at least two insertion parts provided in the second member with a space in between in a longitudinal direction of the other web-like material, to which the other web-like material is inserted.
With this structure, the other web-like material can be fixed in a position of an optional length through inserting the web-like material into one of the insertion part, reversing it then to be inserted into the other insertion part, and then pulling it out to the initial position side of the web-like material.
Furthermore, it is preferable that at least one corner of cross section in a part between the two insertion parts formed in the second member be an acute angle.
In this structure, at least one corner of the cross section in a part between the two insertion parts to which the other web-like material is inserted is formed to be at an acute angle. Therefore, the acute angle part of the tip is to be engaged with the web-like material so that the other web-like material can be surely fixed in a position of an optional length.